Media Dam and Media Path for an Imaging Device

ABSTRACT

A media dam for a media path of an imaging device along which a media sheet traverses according to one example embodiment includes a plurality of inclined rib members. The rib members form a contact surface for engaging and deflecting the media sheet along the media path. The contact surface has a top edge that includes at least one sloped portion.

CROSS REFERENCES TO RELATED APPLICATIONS

None.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

None.

REFERENCE TO SEQUENTIAL LISTING, ETC

None.

BACKGROUND

1. Field of the Disclosure

The present application relates generally to an imaging device and more particularly to a media dam and a media path for an imaging device.

2. Description of the Related Art

In the imaging process used in imaging devices such as printers, copiers, and automatic document feed scanners, a series of rollers and/or belts picks media from a media storage location and advances it along a media path through an image transfer or scanning section of the device. The rollers or belts then advance the media to an output location for collecting media. Various members such as dams or guides define the media path by deflecting the media in a desired direction as it is advanced by the rollers or belts.

As the media advances through the media path it transitions between various adjacent surfaces that define the media path. For example, a feed roller may advance a media sheet from the media storage location into contact with a media dam adjacent to the media storage location that directs the media sheet into the media path. As the media sheet advances, it transitions from the media dam to an outer media guide downstream from the media dam that further directs the media sheet along the media path. The outer media guide may be spaced away from the media dam in order to accommodate additional media paths such as a duplex path or a feed path from a second media storage location.

As the media travels along the media path, it takes the shape of the media path. Some media paths are characterized by geometries that include relatively sharp curvature in order to reduce the overall footprint of the media path thereby permitting a smaller imaging device. In such devices, the media may achieve a cantilevered effect as it prepares to transition from one surface to another, such as from a media dam adjacent to the media storage location to an outer media guide. As the trailing edge of the media transitions from one surface to the next, the media unloads causing an undesired noise as it leaves the first surface and strikes an adjacent surface. This uncontrolled transition is referred to as “tail flip.” The noise associated with a tail flip increases when rigid media, such as photo media, is used.

FIG. 1 illustrates a known media dam 20. The media dam 20 includes a media contact surface 22. The contact surface 22 includes a flat top edge 24 that is substantially parallel with the trailing edge of a media sheet that traverses the media path. As media transitions from the media dam 20 to an adjacent media guide, a tail flip may occur resulting in undesired noise. A gate 26 is disposed immediately downstream from the contact surface 22. The gate 26 directs media entering the media path from the media storage location as well as media exiting a duplex path along the media path. The gate 26 pivots at a pivot point 27 on the bottom end 26 a of the gate 26 such that a top end 26 b is free to rotate. The gate 26 is designed to control the noise that occurs as a result of a tail flip by absorbing the contact from the trailing edge of the media sheet. However, in some instances, the gate 26 may cause a media jam if the leading edge of a media sheet catches on the gate 26.

Accordingly, it will be appreciated that a media dam that reduces the noise associated with a tail flip is desired.

SUMMARY

A media dam for a media path of an imaging device along which a media sheet traverses according to one example embodiment includes a plurality of inclined rib members. The rib members form a contact surface for engaging and deflecting the media sheet along the media path. The contact surface has a top edge that includes at least one sloped portion. In some embodiments, at least some of the plurality of rib members consecutively increase in height. Embodiments include those wherein at least one of the plurality of rib members has a longitudinally sloped top surface. In some embodiments, the top edge of the contact surface is sloped across a length of the contact surface. Embodiments include those wherein the top edge of the contact surface slopes upward from a first end of the contact surface to a second end of the contact surface. Alternatives include those wherein the top edge of the contact surface slopes upward from each of a first end and a second end of the contact surface to a point between the first end and the second end.

A media path for an imaging device along which a media sheet traverses according to one example embodiment includes a media tray having a media storage location for storing a stack of media sheets. An inclined media dam is disposed adjacent to the media storage location. The inclined media dam has at least one member forming a contact surface for engaging and deflecting a media sheet from the media storage location into the media path. The contact surface has a first height at a first location and a second height at a second location different from the first height. A media guide is disposed downstream and spaced away from the media dam such that the media sheet transitions from the media dam to the media guide as the media sheet traverses the media path. In some embodiments, the contact surface has a top edge that is not substantially parallel with a trailing edge of the media sheet as it transitions from the media dam to the media guide.

A media path for an imaging device along which a media sheet traverses according another example embodiment includes a media dam having a contact surface for engaging and deflecting the media sheet along the media path. The media dam is dimensioned such that a time at which a first point of a trailing edge of the media sheet disengages from the contact surface is different from a time at which a second point of the trailing edge of the media sheet disengages from the contact surface.

BRIEF DESCRIPTION OF THE DRAWINGS

The above-mentioned and other features and advantages of the various embodiments, and the manner of attaining them, will become more apparent and will be better understood by reference to the accompanying drawings, wherein:

FIG. 1 shows a front elevation view of a prior art media dam;

FIG. 2 shows a schematic view of a media path for an imaging device according to one embodiment;

FIG. 3 shows an isometric view of a media dam and a media guide according to one embodiment;

FIG. 4 shows an isometric view of a media storage location and a media dam according to one embodiment;

FIG. 5 shows an isometric view of a media storage location and a pick mechanism according to one embodiment;

FIG. 6 a shows a front elevation view of a media dam according to a first example embodiment;

FIG. 6 b shows a side elevation view of the media dam illustrated in FIG. 6 a;

FIG. 7 a shows a front elevation view of a media dam according to a second example embodiment;

FIG. 7 b shows a side elevation view of the media dam illustrated in FIG. 7 a;

FIG. 8 a is a normalized graph showing the noise associated with the trailing edge of a media sheet transitioning between adjacent surfaces in a media path that includes the known media dam illustrated in FIG. 1;

FIG. 8 b is a normalized graph showing the noise associated with the trailing edge of a media sheet transitioning between adjacent surfaces in a media path that includes the media dam illustrated in FIGS. 6 a and 6 b; and

FIG. 8 c is a normalized graph showing the noise associated with the trailing edge of a media sheet transitioning between adjacent surfaces in a media path that includes the media dam illustrated in FIGS. 7 a and 7 b;

FIG. 9 a shows a schematic view of a V-shaped top line profile for a media dam according to one embodiment;

FIG. 9 b shows a schematic view of a concave top line profile for a media dam according to one embodiment; and

FIG. 9 c shows a schematic view of a convex top line profile for a media dam according to one embodiment.

DETAILED DESCRIPTION

The following description and drawings illustrate embodiments sufficiently to enable those skilled in the art to practice it. It is to be understood that the disclosure is not limited to the details of construction and the arrangement of components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. For example, other embodiments may incorporate structural, chronological, electrical, process, and other changes. Examples merely typify possible variations. Individual components and functions are optional unless explicitly required, and the sequence of operations may vary. Portions and features of some embodiments may be included in or substituted for those of others. The scope of the application encompasses the appended claims and all available equivalents. The following description is, therefore, not to be taken in a limited sense, and the scope of the present application is defined by the appended claims.

Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of “including,” “comprising,” or “having” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Unless limited otherwise, the terms “connected,” “coupled,” and “mounted,” and variations thereof herein are used broadly and encompass direct and indirect connections, couplings, and mountings. In addition, the terms “connected” and “coupled” and variations thereof are not restricted to physical or mechanical connections or couplings.

With reference to FIG. 2, an imaging device 40 includes one or more media trays each having a media storage location 42 for storing a stack of media sheets 44. A pick mechanism 46 is operatively engaged with the stack of media sheets 44 to pick a media sheet and advance it into a media path 48. The pick mechanism 46 may include one or more rollers, belts or the like. The media path 48 includes a media feed path 50 for advancing media sheets from the media storage location 42. In some embodiments, the media path 48 also includes a duplex path 52 for duplex printing and/or a second media feed path 54 for advancing media sheets from a second media storage location such as, for example, an option tray disposed below the media storage location 42. In the embodiment illustrated in FIG. 2, a C-shaped media path 48 is illustrated; however, any suitable media path may be used such as, for example, an L-shaped or S-shaped media path. An inclined media dam 56 is disposed adjacent to the media storage location 42. The pick mechanism 46 advances the media sheet into contact with a contact surface of the media dam 56 that engages and deflects the media sheet from the media storage location 42 into the media path 48.

An outer media guide 60 is located downstream from the media dam 56. The outer media guide 60 is spaced away from the media dam 56. The spacing between the media dam 56 and the outer media guide 60 may accommodate a duplex path 52 and/or a second media feed path 54. Each media sheet that is advanced from the media storage location 42 transitions from the media dam 56 to the outer media guide 60. The trailing edge of each media sheet disengages from the media dam 56 and then engages with the outer media guide 60. One or more rollers 62 continue to advance each media sheet through the media path 48. In the embodiment illustrated in FIG. 2, the media sheet is advanced through an image transfer section 64. Image transfer may be achieved through the use of a photosensitive member such as a photosensitive drum or belt, a thermal inkjet device, a piezo-electric inkjet device, dye sublimation or any other image forming technology. Alternative embodiments include those wherein each media sheet is advanced through a scanning section of the imaging device 40. Each media sheet is then advanced to an output location 66 for collecting the media.

With reference to FIGS. 3-5, a media tray 68 according to one embodiment is shown. The media tray 68 includes a bottom surface 70, a front wall 72, and a pair of side walls 74, 76. The walls 72, 74, 76 extend upward from the bottom surface 70 defining the media storage location 42. The pick mechanism 46 is mounted to a frame 78 of the imaging device 40. Embodiments include those wherein the pick mechanism 46 includes a raisable pick arm 80 that allows the pick mechanism 46 to descend onto the stack of media sheets 44 thereby allowing it to feed a topmost media sheet into the media path 48. In some embodiments, the bottom surface 70 of the media tray 68 includes a raisable lift plate for raising the stack of media sheets 44 into contact with the pick mechanism 46. The media dam 56 is disposed adjacent to the media storage location 42. Embodiments include those wherein the media dam 56 is mounted to the frame 78 of the imaging device 40 by a mounting frame 96 (FIGS. 6 b and 7 b) such that the bottom surface 70 of the media tray 68 is disposed adjacent to or abuts the media dam 56 when the media tray 68 is inserted into the imaging device 40. Alternatives include those wherein the media dam 56 is disposed in the media tray 68 and extends upward from the bottom surface 70 and, in some cases, between the side walls 74, 76. While the example embodiments illustrated include a media dam 56 that is disposed adjacent to a media storage location 42, it will be appreciated that the media dam 56 may be disposed at any point along the media path 48 where it is desired to transition a media sheet from one surface to another.

FIGS. 6 a, 6 b, 7 a and 7 b illustrate two example embodiments of the media dam 56. The media dam 56 includes at least one member such as rib member 82. In some embodiments, the media dam 56 includes a plurality of rib members 82. As shown in FIGS. 6 b and 7 b, the rib members 82 may be inclined to deflect each media sheet from the media storage location 42 along the media path 48. The rib members 82 each include a front surface 83 and combine to form a contact surface 58 for engaging and deflecting the media sheet. The contact surface 58 includes a top edge 84 that includes at least one sloped portion 86. The sloped portion 86 may extend across the entire length of the contact surface 58. Alternatively, the sloped portion 86 may extend across a portion of the contact surface 58. Embodiments include those wherein at least some of the rib members 82 consecutively increase or decrease in height. The rib members 82 may increase or decrease in height across the entire length of the contact surface 58.

In the embodiment illustrated in FIGS. 6 a and 6 b, the contact surface 58 has a chevron shaped top line profile 98. The top edge 84 slopes upward from each of a first end 58 a and a second end 58 b to a point 58 c between the first end 58 a and the second end 58 b. The point 58 c is approximately midway between the first end 58 a and the second end 58 b in the embodiment shown; however, alternatives include those wherein the point 58 c is offset to one side or the other. The angle of incline from each of the first end 58 a and the second end 58 b may be any suitable angle taking into account the geometry of the media path 48. In one example embodiment, the angle of incline from each of the first end 58 a and the second end 58 b is about 9°.

In the embodiment illustrated in FIGS. 7 a and 7 b, the contact surface 58 has a straight angled top line profile 98. The top edge 84 slopes upward from the first end 58 a of the contact surface 58 to the second end 58 b. The angle of incline from the first end 58 a to the second end 58 b may be any suitable angle taking into account the geometry of the media path 48. In one example embodiment, the angle of incline from each of the first end 58 a and the second end 58 b is about 5°.

With continued reference to FIGS. 6 a, 6 b, 7 a and 7 b, in some embodiments, the rib members 82 include a longitudinally sloped top surface 88. The longitudinal sloped top surface 88 may include a single planar segment, a curved surface, multiple planar segments that meet at one or more points or lines, or a combination of curved and planar segments. Alternatives include those wherein the rib members have a flat top surface 88. Embodiments include those wherein the media dam 56 is substantially symmetrical as shown in FIGS. 6 a and 6 b. Alternatives include those wherein the media dam 56 is asymmetrical as shown in FIGS. 7 a and 7 b.

The contact surface 58 of the media dam 56 has a height at a first location that is different from the height at a second location. For example, in the embodiment shown in FIG. 6 a, the height of the contact surface 58 at the first end 58 a and the second end 58 b is different than the height at the point 58 c between the first end 58 a and the second end 58 b. Further, in the embodiment shown in FIG. 7 a, the height of the contact surface 58 at the first end 58 a is different than the height of the contact surface 58 at the second end 58 b. In one example embodiment, the height H1 measured along the contact surface 58 from a bottom edge 100 of the media dam 56 of the rib member 82 at a low point 92 of the contact surface 58 is between about 44 mm and about 46 mm and the height H2 measured along the contact surface 58 of the rib member 82 at a high point 94 of the contact surface 58 is between about 58 mm and about 62 mm including all increments and values therebetween. In some embodiments, the height difference H3 between the low point 92 of the contact surface 58 and the high point 94 of the contact surface 58 is at least about 12 mm.

In some embodiments, the sloped portion 86 on the top edge 84 of the contact surface 58 increases the amount of time the trailing edge of each media sheet takes to transition from the media dam 56 to the outer media guide 60. Embodiments include those wherein the top edge 84 of the contact surface 58 is not parallel with the trailing edge of the media sheet as it transitions from the media dam 56 to the outer media guide 60. Rather, the media dam 56 is dimensioned such that a time at which a first point of the trailing edge of the media sheet disengages from the contact surface 58 is different from a time at which a second point of the trailing edge of the media sheet disengages from the contact surface 58. As a result, in some embodiments, the media sheet slides smoothly through the sloped transition instead of springing off the media dam 56 through a tail flip. Accordingly, it will be appreciated by those skilled in the art that the noise associated with a media sheet transitioning from the media dam 56 to the outer media guide 60 may be reduced by providing a sloped transition from the media dam 56. For example, FIGS. 8 a shows the noise associated with the trailing edge of a media sheet disengaging from the known media dam 20 illustrated in FIG. 1. As illustrated in FIGS. 8 b and 8 c, testing has shown that the use of the example embodiments of media dam 58 shown in FIGS. 6 a and b and 7 a and b, respectively, reduced the noise level associated with the trailing edge of a media sheet disengaging from the media dam 58 in comparison with the known media dam 20 illustrated in FIG. 1. It will be appreciated that while the example embodiments illustrated include a chevron-shaped top line profile 98 and a straight angled top line profile 98, any other suitable top line profile 98 that may result in a first portion of a trailing edge of a media sheet disengaging from the contact surface 58 at a time different than that of a second portion of the trailing edge of the media sheet may be utilized such as, for example, a V-shaped top line profile 98 (FIG. 9 a) or a concave (FIG. 9 b) or convex (FIG. 9 c) top line profile 98.

Testing has shown that providing a more continuous contact surface 58 also provides improved acoustic performance. Further, reducing the width of the gaps 90 between each rib member 82 may reduce the noise that occurs when a media sheet transitions from the media dam 56 to the outer media guide 60. However, the use of rib members 82 having gaps 90 between them decreases the drag force exerted on the media sheet by the contact surface 58 in comparison with an entirely continuous contact surface 58. The known media dam 20 shown in FIG. 1 includes rib members 28 that have a gap 30 between them of at least 8 mm. The gap 30 includes recessed portions 32 of the media dam 20. Embodiments of the present application include those wherein the gap 90 between each rib member 82 of the media dam 56 is between about 0.1 mm and about 8 mm including all increments and values therebetween. In some embodiments, at least one of the gaps 90 is less than 8 mm. Embodiments include those wherein one or more of the gaps 90 may include a recessed portion 91 of the media dam 56. Further, the widths of the rib members 28 of the media dam 20 shown in FIG. 1 range from 5.9 mm to 13.9 mm. Embodiments include those wherein each rib member 82 of the media dam 56 has a width that is greater than 5.9 mm and in some cases is at least about 10 mm. Accordingly, it will be appreciated that providing wider rib members 82 with narrower gaps 90 between each rib member may help reduce the noise that occurs when a media sheet transitions from the media dam 56 to the outer media guide 60 while decreasing the drag force exerted on the media sheet by the media dam 56.

The foregoing description of multiple embodiments has been presented for purposes of illustration. It is not intended to be exhaustive or to limit the application to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teaching. It is understood that the invention may be practiced in ways other than as specifically set forth herein without departing from the scope of the claims. It is intended that the scope of the application be defined by the claims appended hereto. 

What is claimed is:
 1. A media dam for a media path of an imaging device along which a media sheet traverses, comprising: a plurality of inclined rib members forming a contact surface for engaging and deflecting the media sheet along the media path, the contact surface having a top edge that includes at least one sloped portion.
 2. The media dam of claim 1, wherein at least some of the plurality of rib members consecutively increase in height.
 3. The media dam of claim 1, further comprising at least one of the plurality of rib members having a longitudinally sloped top surface.
 4. The media dam of claim 1, wherein the top edge of the contact surface is sloped across a length of the contact surface.
 5. The media dam of claim 1, wherein the top edge of the contact surface slopes upward from a first end of the contact surface to a second end of the contact surface.
 6. The media dam of claim 1, wherein the top edge of the contact surface slopes upward from each of a first end and a second end of the contact surface to a point between the first end and the second end.
 7. The media dam of claim 1, further comprising at least one gap between two of the plurality of rib members having a width that is less than 8 mm.
 8. The media dam of claim 1, further comprising at least one of the plurality of rib members having a width that is greater than 5.9 mm.
 9. The media dam of claim 1, wherein a height difference between a low point of the top edge of the contact surface and a high point of the top edge of the contact surface is at least about 12 mm.
 10. A media path for an imaging device along which a media sheet traverses, comprising: a media tray having a media storage location for storing a stack of media sheets; an inclined media dam adjacent to the media storage location having at least one member forming a contact surface for engaging and deflecting a media sheet from the media storage location into the media path, the contact surface having a first height at a first location and a second height at a second location different from the first height; and a media guide downstream and spaced away from the media dam such that the media sheet transitions from the media dam to the media guide as the media sheet traverses the media path.
 11. The media path of claim 10, further comprising the contact surface having a top edge that includes at least one sloped portion.
 12. The media path of claim 11, wherein the top edge is sloped across a length of the contact surface.
 13. The media path of claim 11, wherein the top edge slopes upward from each of a first end and a second end of the contact surface to a point between the first end and the second end.
 14. The media path of claim 10, further comprising the contact surface having a top edge that is not substantially parallel with a trailing edge of the media sheet as it transitions from the media dam to the media guide.
 15. The media path of claim 10, wherein at least some of the plurality of members consecutively increase in height.
 16. The media path of claim 10, wherein the at least one member includes a longitudinally sloped top surface.
 17. A media path for an imaging device along which a media sheet traverses, comprising: a media dam having a contact surface for engaging and deflecting the media sheet along the media path, the media dam being dimensioned such that a time at which a first point of a trailing edge of the media sheet disengages from the contact surface is different from a time at which a second point of the trailing edge of the media sheet disengages from the contact surface.
 18. The media path of claim 17, further comprising the contact surface having an edge on a downstream side of the contact surface that includes at least one sloped portion.
 19. The media path of claim 17, further comprising the contact surface having an edge on a downstream side of the contact surface that is not substantially parallel with the trailing edge of the media sheet as it disengages from the media dam.
 20. The media path of claim 17, further comprising: a media tray having a media storage location for storing a stack of media sheets, the media dam being disposed adjacent to the media storage location for directing a media sheet from the media storage location into the media path; and a media guide downstream and spaced away from the media dam such that the media sheet transitions from the media dam to the media guide as the media sheet traverses the media path. 